Hi,
Just been 'blessed' with a new CEL code - P420 (Catalyst System Efficiency Below Threshold (Bank 1)). My cat is a sports cat (6 months old) and I've just passed an MOT with decent emmisions.
I've read this "the efficiency of the catalytic converter and/or exhaust pipe and/or O2 sensor is not so great". Is this a good description? ie. it's your cat, exhaust or o2 sensor.
Any suggestions about or experience with this code would be great.
Thanks,
Dave
Another one, this has been discussed recently in connection with a turbo.
Basically the sports cats aren't as efficient as the standard cat in keeping heated.
It only has to drop below threshold a couple of times for the code to come up and the weather is turning colder.
Simplest way of overcoming this is to fit an extender to the third O2 sensor.
Thanks, I read that thread, seems the only one that really discusses the code.
Just read this though on a ToyotaNation thread:
"My03 started pushing the code about a year ago. Got the same response from the techs as you. However, the light went out when I spent a week in Florida last July driving on Florida gasoline. Drove home on FL gas, no light. Fill up with Tennessee gas, CEL is on 16 miles later. It aint the cat, it's the ethanol blended gasoline. I suspect the programming genius did not take into account the possibility of the usage of ethanol blended fuel and thus the P0420. I have Honda throwing same code. I employed this fix on both vehicles and no light.
Go to this link: m http://www.honda-tech.com/showthread.php?t=2162522 (http://www.honda-tech.com/showthread.php?t=2162522) m . Follow it exactly and you have a good chance of ridding yourself of the P0420 CEL and saving yourself enough money to go for a nice vacation."
Coincidence has it that i've recently filled up with Total Excellium Super Unleaded to see what difference it has on my engine. It's been said a number of times that the 2zz should be run on 91 RON fuel minimum (regular unleaded). Just read that Excellium is 97 RON!
Could this have caused it? Havn't read the permanent fix talked about as yet.
Ooh, that's a quirk I hadn't thought of!
Luckily I have an Apexi PFC on my car which gets rid of the third O2 sensor.
I've tried Excellium and the car runs nicely, I suppose a cat could behave differently with a different fuel formula especially if the formulation reduces the temperature of the burn.
Quote from: "Wabbitkilla"Luckily I have an Apexi PFC on my car which gets rid of the third O2 sensor.
I wanted to do that but was trying to kep costs down s:( :( s:(
Six months with nothing then the warning light 50mls into using high octane fuel seems quite a coincidence. Maybe if I reset the ECU it will adjust to the different values it's getting.
Always worth a try resetting the ecu s:D :D s:D
Kind of reminds me of The IT Croud ... "Have you tried switching it off and on again?"
Quote from: "Wabbitkilla"Kind of reminds me of The IT Croud ... "Have you tried switching it off and on again?"
s:lol: :lol: s:lol: I work with computers ... unfortunately, it's so true! (includes phones, routers, ECUs ...)
don't beleive the celica has a 3rd 02? are you running with a stock celica ecu for the 2zz?
Yeah, Celica GTS 2zz and ECU. Everything else is not stock Celica.
Is this the baby?
(http://i1111.photobucket.com/albums/h472/dcodrington/MR2/IMAG0226.jpg)
Now reset the ECU. Done about 20ish miles since the P420. Just a matter of waiting to see if comes on again I guess.
Question: Over what sort of time period can you have three P420's until it is flagged up? My exhaust/manifold has always created a lot of pops and bangs (letting off the accelerator and changing gear at low revs) ever since the engine was installed (5 months). Could these have created 3 P420's over a long period of time?
from memory the celica only has 1 02 sensor in the manifold and none post cat
is it wired up properly?
Quote from: "markiii"from memory the celica only has 1 02 sensor in the manifold and none post cat
is it wired up properly?
How does the Celica setup check the cat?
I believe Rogue know what they are doing but there's no harm in checking. Off to Google, don't wait up ...
not all cars check the cat functionality, mrs jap import is another example with no 02 post cat
Ok, from these 2 links, it appears there is 1 pre cat and 1 post cat.
m http://www.newcelica.org/forums/showthread.php?t=135889 (http://www.newcelica.org/forums/showthread.php?t=135889) m
m http://wiki.answers.com/Q/How_many_oxyg ... Celica_GTS (http://wiki.answers.com/Q/How_many_oxygen_sensors_are_in_a_2000_Toyota_Celica_GTS) m
I now have the question, why do I have 2 pre cat? s:? :? s:?
Quote from: "dcod"Ok, from these 2 links, it appears there is 1 pre cat and 1 post cat.
m http://www.newcelica.org/forums/showthread.php?t=135889 (http://www.newcelica.org/forums/showthread.php?t=135889) m
m http://wiki.answers.com/Q/How_many_oxyg ... Celica_GTS (http://wiki.answers.com/Q/How_many_oxygen_sensors_are_in_a_2000_Toyota_Celica_GTS) m
I now have the question, why do I have 2 pre cat? s:? :? s:?
Darned good question.
The standard 2 has 2 precat, for bank1 & bank2, my guessing is that the 2ZZ swap manifold has both positions too - just how they're wired up is something only Rogue can tell you.
a question for rogue I'm afraid, I don't knw how/why Patrick chooses to wire it the way he does
actually from memory Patrick uses the standard roadster manifold with a new flange (never understood why as one set of ports is oval and the other round)
however, that leaves 2 precat chambers which will have half of the exhaust gas each.
I assume that he needs to sum the output somewhere/somehow in order to feed a single signal back to the Celica ECU whih is expecting a single sensor
Thanks for your help and replies.
My manifold is from ebay with the Celica flange welded on ... as far as I remember.
(http://i1111.photobucket.com/albums/h472/dcodrington/MR2/IMAG0219.jpg)
Just checking to see if a 2004 Celica GTS is any different as those other 2 links are about a 2000 GTS.
It appears that the Celica GTS pre cat sensor is in the mid pipe (between the exhaust manifold and the cat, under the car). So you are correct, they all seem to have only 2 (1 pre and 1 post cat).
I may ask Rogue how they wired in 2 pre cat sensors.
Would a pinout of the GTS ECU show that it can handle 2 pre-cat sensors? Does the pinout of the 1zz show that? Unfortunately, I can't find either at the mo.
Quote from: "dcod"It appears that the Celica GTS pre cat sensor is in the mid pipe (between the exhaust manifold and the cat, under the car). So you are correct, they all seem to have only 2 (1 pre and 1 post cat).
I may ask Rogue how they wired in 2 pre cat sensors.
Would a pinout of the GTS ECU show that it can handle 2 pre-cat sensors? Does the pinout of the 1zz show that? Unfortunately, I can't find either at the mo.
celica ecu can't handle 2 pre-cat sensors, pin outs in the library
Quote from: "markiii"celica ecu can't handle 2 pre-cat sensors, pin outs in the library
Thanks. Always thought I should have spent more time in the library than on the streets ...
Out of interest have you noticed when the MIL comes on (in terms of driving style etc..)?
I am pretty sure that the p0420 is on a 3-trip logic, but not sure if that has to be 3 consecutive cold-hot drive cycles though. Also not sure exactly what drive-cycle is required to complete the cat efficiency check but I would guess that it is combination of urban and motorway style driving.
I have found it hard to work out the root cause of my issue without knowing all the entry and trigger conditions for the diagnostic, but that is all probably buried at the bottom of a filing cabinet in Toyota HQ now!
Interesting to hear that you have a lot of popping/banging on overrun, could be a sign of things being a little too rich under certain conditions and 'flooding' the exhaust/CAT/o2 sensors with HCs that the sports CAT just can't deal with in time to avoid pre/post sensors seeing a similar change....
Although you are NA with different engine it is possible that we are both seeing the same issue, I am not completely convinced yet that mine is just down to sports CAT sensitivity, but would be very happy to be proven wrong! With no other codes/symptoms being flagged then i don't think it is too much to worry about.
Andy
Quote from: "andywood"Interesting to hear that you have a lot of popping/banging on overrun
Bit of a drift really but I had a new exhaust fitted to our camper van last month and then did 1500 miles in Europe. The popping and banging on overrun or when changing down, even at low speeds, was like a machine gun, embarrassing when driving through towns etc.
Took it back to the garage and they said air was getting back into the system. (could be sbollocks bollocks sbollocks really, more likely the dynamics of the new box which are different from the original).
They are fitting a new back box on Thursday which is a different design so I'll wait and see.
Dcod..
Your Exhaust Manifold is Manufactured to Look like a 1ZZ Exhaust System.. and Should actually have the Bolt Holes to hold the 1ZZ Heat Shields.. some Governments get funny about engine changes.. and this exhaust system will keep them from looking deeper into the engine compartment..
When a 2ZZ Swap is done, the Right Side O2 Sensor on the Engine, is the Only One actually used.. the Left Side, just fills up the Holes, and looks Pretty for the Government Inspectors.. You can pull the Electrical Plug for the Left Side and have no ill effects..
The 420 Code is tossed when the Rich/ Lean wave form Frequency reaches a certain Frequency.. As the ECU is fueling the Engine, the Air Fuel Ratio is being forced to Swing above then Below the 14.7 AFR Mark..
You can see the 'Wavy Pink Line' on this Chart.. that is the AFR of a Steady Run down the Road.. The Brown Line behind it is the AFR after the Main Cat..
[Second and Third lines ]
(http://i312.photobucket.com/albums/ll351/CapWeir/PostCruse.jpg)
The 'Dithering' has the Function of Loading up the Cat Converter with O2 when the Fuel Ratio is on the Lean Swing ( Going Up ), then when the AFR's go below the 14.7 Mark, they are loading up the Cat Converter with Fuel..
This Constant Swing has a Frequency that is Monitored by the ECU, and it will look at the After Cat Sensor to watch it's AFR Swing Also.. ( It Also has a Period, that is Slower, and not as pronounced in amplitude )..
As the Converter Ages, the Frequency of this Waveform Increases. When this Period gets to a 'Value' as programmed by the Wizards in japan, then a 420 code is tossed..
When Oxygen enriched Petrol is used, then the Period of the Cat Waveform slows down.. and the Cell is Averted..
Here is a Chart where the 'Dithering' has been smoothed by software ( Averaged ) .. The Pink Line is still the AFR's but Smoothed.. and the Brown Line is the AFR's taken after the Cat with a Wideband Sensor..
[ Second and third Lines ]
(http://i312.photobucket.com/albums/ll351/CapWeir/PostCruseSmoothed.jpg)
You will also notice the AFR's do not 'Overlay'.. as the Two O2 Sensors ( Both LC-1's ) were not calibrated at the Same time.. but are withinn .3 or so of each other.. Close enough for me..
Another 'Fix' for the Dreaded 420 code involves adding a Capicator and resistor to the O2 Sensor feed line to the ECU.. this will have the Effect of slowing down the Waveform ( Low Pass Filter ), and the Results are the Same.. No Cell.. If the Wiring is done at the ECU, then the Government Inspectors have to tear the Car Apart to find it.. so it's cleaner looking that the 'Anti-Fowlers' trick..
Another way is to use a Wide Band O2 Sensor ( Like I Did ) and use it's analog Output to drive the ECU's Circuit.. and Before you install the Wideband Sensor.. Program the Output to be Time Averaged.. this has the Same Effect as Adding the Low Pass Filter..
This After Cat Install of the Wide Band went VERY smoothly.. and I was able to power it from the O2 Sensor Plug.. Just a Few Hiccups on the Power Issue, but I was ultimately able to Make the ECU happy to let me share the 12 Power for my LC-1 Controls.. and it thinks is Powering a standard O2 Sensor.. and it's all Plug and Play.. No Wire Cutting..
This is a Shot of the 'Quick and Dirty' Install..
(http://i312.photobucket.com/albums/ll351/CapWeir/IMG_1247.jpg)
Here is the Thread on Newcelica about the Resistor and Cap Method..
m http://www.newcelica.org/forums/showthread.php?t=216641 (http://www.newcelica.org/forums/showthread.php?t=216641) m
The thread gets off onto some Bad Information.. then later on an EE Comes in and sets the Record Straight..
Cap
Pretty sure mine is wired up with two pre cat sensors, they are in different positions to dcods. Will take ampeek at lunch time.
caps post can't be correct in this instance or the 02 in teh manifold would only be reading gasses from 2 cylinders
Quote from: "markiii"caps post can't be correct in this instance or the 02 in the manifold would only be reading gasses from 2 cylinders
Unless that's the RISK they take, and therefore it's not unfeasible that overall fuelling could be innacurate and therefore you get the false alarm of the cat under-performing. Stands to reason that with a 2ZZ in place it would be best to put the single O2 sensor in the pipe after the collectors befor the cat.
Quote from: "Wabbitkilla"Quote from: "markiii"caps post can't be correct in this instance or the 02 in the manifold would only be reading gasses from 2 cylinders
Unless that's the RISK they take, and therefore it's not unfeasible that overall fuelling could be innacurate and therefore you get the false alarm of the cat under-performing. Stands to reason that with a 2ZZ in place it would be best to put the single O2 sensor in the pipe after the collectors befor the cat.
well if it is I'd never buy a conversion from them.
way back when these were pioneered on SC they were done properly
Quote from: "andywood"Out of interest have you noticed when the MIL comes on (in terms of driving style etc..)?
Interesting to hear that you have a lot of popping/banging on overrun, could be a sign of things being a little too rich under certain conditions and 'flooding' the exhaust/CAT/o2 sensors with HCs that the sports CAT just can't deal with in time to avoid pre/post sensors seeing a similar change....
Hi Andy,
The code has only come on once so far. In the middle of a 20 minute drive starting with 10 minutes urban and the rest motorway (gunning it a little) which is when it came on.
A friend of mine has said my car smelled a little rich when I drove past him once.
When my car was installed, I think the MAF from the celica was used (which had been sitting around for 1-2 months). I've got to get a round to cleaning. It's not as easy to get to now, I've got to take the whole pipe and filter off.
Thanks Cap for your detailed post. I think I'll need to read that a couple of times. Great info.
dcod.
As you see I've been Collecting and testing for a While..
As for the Exhaust Header.. the Sole Purpose for the Existence, is Ease of Install.. and to pass the First Blush test by the Gov .. If all four Fuel Injectors are Clean, then the Fueling will be close.. and 'Close' is good enough .. Except when it comes to Smog Stuff.. then it needs to be Closer..
I agree that the O2 Sensor should to be Placed where it will Snif all Four Pipes.. But only for Smog Reasons.. as the O2 Sensor is there to Add in proper Fueling for the Cat Converter.. NOT FOR PERFORMANCE!!!.. ( 14.7 AFR for Smog Vs 13.5 AFR for Performance ).. if the O2 Sensor was for Performance, then there would be One O2 Sensor Per Cylinder.. Like the Land Speed Record Cars do Now..
If you really still think the Left Side O2 Sensor is Working on your 2ZZ Swap Motor.... Pull the Plug on it, and See what Happens..
Cap
some serious misinformation here
what is "commonly" done in the US to pass CAlI inspections is irelevant to what Rogue may or may not have done in the UK
even then only reading 2 cylinders with the 02 is just asking to blow your engine as you will have NO indication as to whether the other 2 cylinders are running rich or lean
How is it more Dangerous to to read Two Cylinders VS Four Cylinders..
When you are reading a combined Gas Stream, the Reading you are getting is an Average of the Gasses.. So the O2 Sensor is not Accurately reading ANY of the Cylinders.
Is it More Dangerous to Not Accurately Read Two Cylinders, or Four?..
My Information is Correct.. it's your Perception or Reality that is off..
Please point out the Information that is Error..
Cap
the error is your stating what happens by some unspecified installers in the US
nether you nor I nor dcod know how Rogue chose to install this one. Therefore your information is pure speculation with regards to dcods install
Quote from: "Cap"How is it more Dangerous to to read Two Cylinders VS Four Cylinders..
When you are reading a combined Gas Stream, the Reading you are getting is an Average of the Gasses.. So the O2 Sensor is not Accurately reading ANY of the Cylinders.
Is it More Dangerous to Not Accurately Read Two Cylinders, or Four?..
Cap
imho 2 is worse than 4
if your reading all of the cylinders your correcting each cylinder based on the mixed results of 4 cylinders as opposed to reading 2 cylinders where you aren't seeing teh gas flow from the other 2 cylinders at all, your not even averaging in that case its just a complete guess
I agree.. This is Speculation on my part. I have never meat any of the People Involved, and it's likely I never will..
But if this picture as posted is of dcods Car, then it's using a Header that was first MFG in the States for the Reasons Mentioned.. And if dcods Car only has Three Total O2 Sensors, and the 'Third' O2 is Giving him a 420 Code, then it's Likely that the Third O2 Sensor is being used for the B1B2 Sensor. The Header Shown, has Two Sets of Two Cylinders, that have an O2 Sensor per Set.
The Celica ECU only has Inputs From O2 Sensors for the B1S1, and B1S2 Sensors. That is TWO inputs Possible.
I have Speculated that the After Cat Sensor is Hooked to the B1S2 Sensor Input as it Should be. This has Left 2, O2 Sensors that are Mounted in the Header, to be used as Possible Inputs for a Single Input in the B1S1 Position on the ECU.
I Speculate from my Past Dealings with Analogs O2 Sensors, that it's not possible to Sum the Signal from two Analogue O2 Sensors, and get useable Data. You can get Data, but it will only Show the Leanest Signal, not the Average ( Lean is Higher Voltage )
So I speculate that the 2ZZ Installed in dcods Car, by Rogue, using the 1ZZ Lookalike bolt in Header , is installed the Same way it's done in the States, and that is using the Right Side O2 Sensor. As if you follow the Wiring for the Right Side O2 Sensor up to the ECU for the Spyder, is input is B1S1. And for the Celica ECU, the B1S1 O2 Sensor is in the Same Location on the ECU Plugs.
I ASUME that Rogue did not re-pin the ECU Harness to use the Left Side O2 Sensor ( Pure Speculation on My Part ). So my Speculation still is if you Pull the Left Side O2 Sensor Plug, the Car will behave the SAME..
The Proof is to Pull it and Try it.
Cap
Quote from: "Cap"But if this picture as posted is of dcods Car, then it's using a Header that was first MFG in the States for the Reasons Mentioned..
Cap
Quote from: "dcod"My manifold is from ebay with the Celica flange welded on ... as far as I remember.
except for the fact that he already stated above its NOT the 1zz lookalike header you refer to
Oh bugger ... it's all speculation till dcod finds out how Rogue wired it so there's no point in getting wound up about it.
Either way P0420 is the cat under-performaing for any number of reason, most likely it's just cooling too much and bringing the light up for occassional drops.
Sports cats do have a habit of doing this due to their size, coping with it is what we're after really ... anti fouler, filter, or fit a PFC and get rid of it.
Actually this has brought up a good Point..
If the 2ZZ Swap is running ONLY the Right side O2 Sensor, then it's < Likely> that the 420 MIGHT be Bogus, as the Fueling ECU is only Snifing two Cylinders, and the After Cat is Actually Sniffing the Combined of all Four. Two are Sneeking in on the After Cat Read..
So I Speculate that the Improper Fueling of the engine MIGHT be tripping the 420 .. and 420 was the Origional Complaint.
So to take it further.. I Speculate that if the O2 Sensor Input for B1S1 is moved to where all Four Gas Flows can be Read, then the 420 MIGHT go away..
Cap
so you agree sniffing 2 cylinders is worse than 4 then? :-) :-) :-)
Quote from: "markiii"so you agree sniffing 2 cylinders is worse than 4 then? :-) :-) :-)
I agree that sniffing two VS Four will have different outcoms..
For SMOG Reasions, I said all the Cylinders must be Sniffed, then fueling will Cycle Above and Below the Magic 14.7 Mark.. and the Smog Kings are Happy.. This will do Nothing tyo reduce the Risk of a Lean Cylinder.. and the Damage that can Result..
For Performance, I said One O2 Sensor per Cylinder is best.. as this is the Only Way to Eliminate the Lean Cylinder Risk.. But for Smog.. this is not desirable without some Software Tricks..
For Performance .. anything other than One o2 Sensor per Cylinder is a Risk..
Cap
I'll try and give Rogue a call tomorrow (thursday) and find out how they have wired it up. Anything anyone wants to know in particular?
Play nice while I'm gone.
Oh, and the P420 came up again today. So I don't think the other was a one off. s:( :( s:(
Any Update to the theories and postulations ?
Cap
Hi Cap,
Called Rogue on Thursday but the guy who does the wiring had just left for Anglesea (possible for a race meet) and the mechanic couldn't remember if the O2 sensors are spliced together or one is a dummy. They are going to call me back after the weekend.
Just pretty much emptied the high octane fuel from my tank on a smile enducing drive through the New Forest and have now filled up with regular unleaded. I've got to do the same journey tomorrow, to pick up my hung over wife after a night on the town in Bournemouth, and shall see if the code is highlighted again.
If I find that one O2 sensor is not wired up then I may swap them over and see if the 'spare' makes any difference.
Quote from: "dcod"Just pretty much emptied the high octane fuel from my tank on a smile enducing drive through the New Forest
I see you are using the 2 + 2ZZ in a use for which they were intended .. s:) :) s:)
Thanks for the Update..
Cap
It is indeed great fun on the twisties. I love lift, you can't help but smile when you hear the grumble kick in
Quote from: "Ilogik"It is indeed great fun on the twisties. I love lift, you can't help but smile when you hear the grumble kick in
I want to spend my life flitting in and out of lift ... in a tunnel s:D :D s:D
With my exhaust, I even had Porsches and Ferrari staring at me! Especially the idiots who spent £80,000+ on a car that isn't a convertible.
Hi,
SInce returning to regular unleaded, I've made two 45 minute motorway journeys and no P420. These journeys were type that would give me the code before without fail.
Solved? Maybe. Only time will tell.
Dave
Ive been watching this post with interest. Simple question from a simple bloke. How does the O2 sensor work? s:?: :?: s:?:
m http://en.wikipedia.org/wiki/Oxygen_sensor (http://en.wikipedia.org/wiki/Oxygen_sensor) m
Andy
P420 back s:( :( s:(
So I deduce that it wasn't the high octane fuel I put in. It may have something to do with my other thread and my oil burning.
Now going back into investigative mode.
Oil + Catalytic convert are not a match made in heaven unfortunately.